Is there an endpoint I can call to send association request for Vertex AI Project?

The Google Site Verification API documentation does not seem to provide options for sending association requests. I also explored the Discovery Engine API, and while I can retrieve SiteVerificationInfo and refresh verifications for target sites, there is no way to request association via the client.

As a last attempt, I tried making a direct call to the endpoint found in the Google Search Console Data Store UI that sends the association requests (https://discoveryengine.googleapis.com/v1alpha/projects/{project}/locations/global/collections/default_collection/dataStores/{data_store_id}/siteSearchEngine/targetSites/{target_site_id}:requestDomainAssociations), but the request fails/is not accessible.

Is there a way to automate sending these association requests, ideally through an API that can be called from our Python service?